Vacuum adiabatic body and refrigerator

ABSTRACT

A vacuum adiabatic body includes a first plate; a second plate; a seal; a support; a heat resistance unit; and an exhaust port, wherein the heat resistance unit includes a conductive resistance sheet connected to at least one of the first and second plates, the conductive resistance sheet resisting heat conduction flowing along a wall for the third space, the conductive resistance sheet includes a mounting part mounted on the first or second plate and a curved part having at least one portion depressed into the third space, a coupler that fixes the conductive resistance sheet to the first or second plate is formed on the mounting part, and the curved part includes a first curved part depressed toward the third space and a second curved part extending from the first curved part, the second curved part surrounding an edge portion of the first or second plate.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a Divisional Application of U.S. patent applicationSer. No. 15/749,147 filed Jan. 31, 2018, which is a U.S. National StageApplication under 35 U.S.C. § 371 of PCT Application No.PCT/KR2016/008516, filed Aug. 2, 2016, which claims priority to KoreanPatent Application No. 10-2015-0109624, filed Aug. 3, 2015, whose entiredisclosures are hereby incorporated by reference

BACKGROUND 1. Field

The present disclosure relates to a vacuum adiabatic body and arefrigerator.

2. Background

A vacuum adiabatic body is a product for suppressing heat transfer byvacuumizing the interior of a body thereof. The vacuum adiabatic bodycan reduce heat transfer by convection and conduction, and hence isapplied to heating apparatuses and refrigerating apparatuses. In atypical adiabatic method applied to a refrigerator, although it isdifferently applied in refrigeration and freezing, a foam urethaneadiabatic wall having a thickness of about 30 cm or more is generallyprovided. However, the internal volume of the refrigerator is thereforereduced. In order to increase the internal volume of a refrigerator,there is an attempt to apply a vacuum adiabatic body to therefrigerator.

First, Korean Patent No. 10-0343719 (Reference Document 1) of thepresent applicant has been disclosed. According to Reference Document 1,there is disclosed a method in which a vacuum adiabatic panel isprepared and then built in walls of a refrigerator, and the exterior ofthe vacuum adiabatic panel is finished with a separate molding such asStyrofoam (polystyrene). According to the method, additional foaming isnot required, and the adiabatic performance of the refrigerator isimproved. However, manufacturing cost is increased, and a manufacturingmethod is complicated.

As another example, a technique of providing walls using a vacuumadiabatic material and additionally providing adiabatic walls using afoam filling material has been disclosed in Korean Patent PublicationNo. 10-2015-0012712 (Reference Document 2). According to ReferenceDocument 2, manufacturing cost is increased, and a manufacturing methodis complicated.

As another example, there is an attempt to manufacture all walls of arefrigerator using a vacuum adiabatic body that is a single product. Forexample, a technique of providing an adiabatic structure of arefrigerator to be in a vacuum state has been disclosed in U.S. PatentLaid-Open Publication No. US 2004/0226956 A1 (Reference Document 3).

However, it is difficult to obtain an adiabatic effect of a practicallevel by providing the walls of the refrigerator to be in a sufficientvacuum state. Specifically, it is difficult to prevent heat transfer ata contact portion between external and internal cases having differenttemperatures. Further, it is difficult to maintain a stable vacuumstate. Furthermore, it is difficult to prevent deformation of the casesdue to a sound pressure in the vacuum state. Due to these problems, thetechnique of Reference Document 3 is limited to cryogenic refrigeratingapparatuses, and is not applied to refrigerating apparatuses used ingeneral households.

BRIEF DESCRIPTION OF THE DRAWINGS

The embodiments will be described in detail with reference to thefollowing drawings in which like reference numerals refer to likeelements wherein:

FIG. 1 is a perspective view of a refrigerator according to anembodiment.

FIG. 2 is a view schematically showing a vacuum adiabatic body used in amain body and a door of the refrigerator.

FIG. 3 is a view showing various embodiments of an internalconfiguration of a vacuum space part.

FIG. 4 is a view showing various embodiments of conductive resistancesheets and peripheral parts thereof.

FIG. 5 is a sectional view of a conductive resistance sheet and a firstplate member.

FIG. 6 is a graph illustrating a design reference of the conductiveresistance sheet.

FIG. 7 is a view showing a state in which atmospheric pressure isapplied to the conductive resistance sheet.

FIG. 8 is a view illustrating a relationship between the atmosphericpressure and a tension applied to the conductive resistance sheet.

FIG. 9 illustrates graphs showing changes in adiabatic performance andchanges in gas conductivity with respect to vacuum pressures by applyinga simulation.

FIG. 10 illustrates graphs obtained by observing, over time andpressure, a process of exhausting the interior of the vacuum adiabaticbody when a supporting unit is used.

FIG. 11 illustrates graphs obtained by comparing vacuum pressures andgas conductivities.

DETAILED DESCRIPTION

Reference will now be made in detail to the embodiments of the presentdisclosure, examples of which are illustrated in the accompanyingdrawings.

In the following detailed description of the preferred embodiments,reference is made to the accompanying drawings that form a part hereof,and in which is shown by way of illustration specific preferredembodiments in which the disclosure may be practiced. These embodimentsare described in sufficient detail to enable those skilled in the art topractice the disclosure, and it is understood that other embodiments maybe utilized and that logical structural, mechanical, electrical, andchemical changes may be made without departing from the spirit or scopeof the disclosure. To avoid detail not necessary to enable those skilledin the art to practice the disclosure, the description may omit certaininformation known to those skilled in the art. The following detaileddescription is, therefore, not to be taken in a limiting sense.

In the following description, the term ‘vacuum pressure’ means a certainpressure state lower than atmospheric pressure. In addition, theexpression that a vacuum degree of A is higher than that of B means thata vacuum pressure of A is lower than that of B.

FIG. 1 is a perspective view of a refrigerator according to anembodiment. FIG. 2 is a view schematically showing a vacuum adiabaticbody used in the main body and the door of the refrigerator. In FIG. 2,a main body-side vacuum adiabatic body is illustrated in a state inwhich top and side walls are removed, and a door-side vacuum adiabaticbody is illustrated in a state in which a portion of a front wall isremoved. In addition, sections of portions at conductive resistancesheets are provided are schematically illustrated for convenience ofunderstanding.

Referring to FIGS. 1 and 2, the refrigerator 1 includes a main body 2provided with a cavity 9 capable of storing storage goods and a door 3provided to open/close the main body 2. The door 3 may be rotatably ormovably disposed to open/close the cavity 9. The cavity 9 may provide atleast one of a refrigerating chamber and a freezing chamber.

Parts constituting a freezing cycle in which cold air is supplied intothe cavity 9 may be included. Specifically, the parts include acompressor 4 for compressing a refrigerant, a condenser 5 for condensingthe compressed refrigerant, an expander 6 for expanding the condensedrefrigerant, and an evaporator 7 for evaporating the expandedrefrigerant to take heat. As a typical structure, a fan may be installedat a position adjacent to the evaporator 7, and a fluid blown from thefan may pass through the evaporator 7 and then be blown into the cavity9. A freezing load is controlled by adjusting the blowing amount andblowing direction by the fan, adjusting the amount of a circulatedrefrigerant, or adjusting the compression rate of the compressor, sothat it is possible to control a refrigerating space or a freezingspace.

The vacuum adiabatic body includes a first plate member (or first plate)10 for providing a wall of a low-temperature space, a second platemember (or second plate) 20 for providing a wall of a high-temperaturespace, and a vacuum space part (or vacuum space) 50 defined as a gappart between the first and second plate members 10 and 20. Also, thevacuum adiabatic body includes the conductive resistance sheets 60 and62 for preventing heat conduction between the first and second platemembers 10 and 20.

A sealing part (or seal) 61 for sealing the first and second platemembers 10 and 20 is provided such that the vacuum space part 50 is in asealing state. When the vacuum adiabatic body is applied to arefrigerating or heating cabinet, the first plate member 10 may bereferred to as an inner case, and the second plate member 20 may bereferred to as an outer case. A machine chamber 8 in which partsproviding a freezing cycle are accommodated is placed at a lower rearside of the main body-side vacuum adiabatic body, and an exhaust port 40for forming a vacuum state by exhausting air in the vacuum space part 50is provided at any one side of the vacuum adiabatic body. In addition, apipeline 64 passing through the vacuum space part 50 may be furtherinstalled so as to install a defrosting water line and electric lines.

The first plate member 10 may define at least one portion of a wall fora first space provided thereto. The second plate member 20 may define atleast one portion of a wall for a second space provided thereto. Thefirst space and the second space may be defined as spaces havingdifferent temperatures. Here, the wall for each space may serve as notonly a wall directly contacting the space but also a wall not contactingthe space. For example, the vacuum adiabatic body of the embodiment mayalso be applied to a product further having a separate wall contactingeach space.

Factors of heat transfer, which cause loss of the adiabatic effect ofthe vacuum adiabatic body, are heat conduction between the first andsecond plate members 10 and 20, heat radiation between the first andsecond plate members 10 and 20, and gas conduction of the vacuum spacepart 50.

Hereinafter, a heat resistance unit provided to reduce adiabatic lossrelated to the factors of the heat transfer will be provided. Meanwhile,the vacuum adiabatic body and the refrigerator of the embodiment do notexclude that another adiabatic means is further provided to at least oneside of the vacuum adiabatic body. Therefore, an adiabatic means usingfoaming or the like may be further provided to another side of thevacuum adiabatic body.

FIG. 3 is a view showing various embodiments of an internalconfiguration of the vacuum space part. First, referring to FIG. 3a ,the vacuum space part 50 is provided in a third space having a differentpressure from the first and second spaces, preferably, a vacuum state,thereby reducing adiabatic loss. The third space may be provided at atemperature between the temperature of the first space and thetemperature of the second space. Since the third space is provided as aspace in the vacuum state, the first and second plate members 10 and 20receive a force contracting in a direction in which they approach eachother due to a force corresponding to a pressure difference between thefirst and second spaces. Therefore, the vacuum space part 50 may bedeformed in a direction in which it is reduced. In this case, adiabaticloss may be caused due to an increase in amount of heat radiation,caused by the contraction of the vacuum space part 50, and an increasein amount of heat conduction, caused by contact between the platemembers 10 and 20.

A supporting unit (or support) 30 may be provided to reduce thedeformation of the vacuum space part 50. The supporting unit 30 includesbars 31. The bars 31 may extend in a direction substantially vertical tothe first and second plate members 10 and 20 so as to support a distancebetween the first and second plate members 10 and 20. A support plate 35may be additionally provided to at least one end of the bar 31. Thesupport plate 35 connects at least two bars 31 to each other, and mayextend in a direction horizontal to the first and second plate members10 and 20.

The support plate 35 may be provided in a plate shape, or may beprovided in a lattice shape such that its area contacting the first orsecond plate member 10 or 20 is decreased, thereby reducing heattransfer. The bars 31 and the support plate 35 are fixed to each otherat at least one portion, to be inserted together between the first andsecond plate members 10 and 20. The support plate 35 contacts at leastone of the first and second plate members 10 and 20, thereby preventingdeformation of the first and second plate members 10 and 20.

In addition, based on the extending direction of the bars 31, a totalsectional area of the support plate 35 is provided to be greater thanthat of the bars 31, so that heat transferred through the bars 31 can bediffused through the support plate 35. A material of the supporting unit30 may include a resin selected from the group consisting of PC, glassfiber PC, low outgassing PC, PPS, and LCP so as to obtain highcompressive strength, low outgassing and water absorptance, low thermalconductivity, high compressive strength at high temperature, andexcellent machinability.

A radiation resistance sheet 32 for reducing heat radiation between thefirst and second plate members 10 and 20 through the vacuum space part50 will be described. The first and second plate members 10 and 20 maybe made of a stainless material capable of preventing corrosion andproviding a sufficient strength. The stainless material has a relativelyhigh emissivity of 0.16, and hence a large amount of radiation heat maybe transferred.

In addition, the supporting unit 30 made of the resin has a loweremissivity than the plate members, and is not entirely provided to innersurfaces of the first and second plate members 10 and 20. Hence, thesupporting unit 30 does not have great influence on radiation heat.Therefore, the radiation resistance sheet 32 may be provided in a plateshape over a majority of the area of the vacuum space part 50 so as toconcentrate on reduction of radiation heat transferred between the firstand second plate members 10 and 20.

A product having a low emissivity may be preferably used as the materialof the radiation resistance sheet 32. In an embodiment, an aluminum foilhaving an emissivity of 0.02 may be used as the radiation resistancesheet 32. Since the transfer of radiation heat cannot be sufficientlyblocked using one radiation resistance sheet, at least two radiationresistance sheets 32 may be provided at a certain distance so as not tocontact each other. In addition, at least one radiation resistance sheetmay be provided in a state in which it contacts the inner surface of thefirst or second plate member 10 or 20.

Referring to FIG. 3b , the distance between the plate members ismaintained by the supporting unit 30, and a porous material 33 may befilled in the vacuum space part 50. The porous material 33 may have ahigher emissivity than the stainless material of the first and secondplate members 10 and 20. However, since the porous material 33 is filledin the vacuum space part 50, the porous material 33 has a highefficiency for blocking the transfer of radiation heat. In thisembodiment, the vacuum adiabatic body can be manufactured without usingthe radiation resistance sheet 32.

Referring to FIG. 3c , the supporting unit 30 maintaining the vacuumspace part 50 is not provided. Instead of the supporting unit 30, theporous material 33 is provided in a state in which it is surrounded by afilm 34. In this case, the porous material 33 may be provided in a statein which it is compressed so as to maintain the gap of the vacuum spacepart 50. The film 34 is made of, for example, a PE material, and may beprovided in a state in which holes are formed therein.

In this embodiment, the vacuum adiabatic body can be manufacturedwithout using the supporting unit 30. In other words, the porousmaterial 33 can serve together as the radiation resistance sheet 32 andthe supporting unit 30.

FIG. 4 is a view showing various embodiments of the conductiveresistance sheets and peripheral parts thereof. Structures of theconductive resistance sheets are briefly illustrated in FIG. 2, but willbe understood in detail with reference to FIG. 4.

First, a conductive resistance sheet proposed in FIG. 4a may bepreferably applied to the main body-side vacuum adiabatic body.Specifically, the first and second plate members 10 and 20 are to besealed so as to vacuumize the interior of the vacuum adiabatic body. Inthis case, since the two plate members have different temperatures fromeach other, heat transfer may occur between the two plate members. Aconductive resistance sheet 60 is provided to prevent heat conductionbetween two different kinds of plate members.

The conductive resistance sheet 60 may be provided with sealing parts 61at which both ends of the conductive resistance sheet 60 are sealed todefine at least one portion of the wall for the third space and maintainthe vacuum state. The conductive resistance sheet 60 may be provided asa thin foil in units of micrometers so as to reduce the amount of heatconducted along the wall for the third space. The sealing parts 61 maybe provided as welding parts. That is, the conductive resistance sheet60 and the plate members 10 and 20 may be fused to each other.

In order to cause a fusing action between the conductive resistancesheet 60 and the plate members 10 and 20, the conductive resistancesheet 60 and the plate members 10 and 20 may be made of the samematerial, and a stainless material may be used as the material. Thesealing parts 61 are not limited to the welding parts, and may beprovided through a process such as cocking. The conductive resistancesheet 60 may be provided in a curved shape. Thus, a heat conductiondistance of the conductive resistance sheet 60 is provided longer thanthe linear distance of each plate member, so that the amount of heatconduction can be further reduced.

A change in temperature occurs along the conductive resistance sheet 60.Therefore, in order to block heat transfer to the exterior of theconductive resistance sheet 60, a shielding part (or shield) 62 may beprovided at the exterior of the conductive resistance sheet 60 such thatan adiabatic action occurs. In other words, in the refrigerator, thesecond plate member 20 has a high temperature and the first plate member10 has a low temperature. In addition, heat conduction from hightemperature to low temperature occurs in the conductive resistance sheet60, and hence the temperature of the conductive resistance sheet 60 issuddenly changed. Therefore, when the conductive resistance sheet 60 isopened to the exterior thereof, heat transfer through the opened placemay seriously occur.

In order to reduce heat loss, the shielding part 62 is provided at theexterior of the conductive resistance sheet 60. For example, when theconductive resistance sheet 60 is exposed to any one of thelow-temperature space and the high-temperature space, the conductiveresistance sheet 60 does not serve as a conductive resistor as well asthe exposed portion thereof, which is not preferable.

The shielding part 62 may be provided as a porous material contacting anouter surface of the conductive resistance sheet 60. The shielding part62 may be provided as an adiabatic structure, e.g., a separate gasket,which is placed at the exterior of the conductive resistance sheet 60.The shielding part 62 may be provided as a portion of the vacuumadiabatic body, which is provided at a position facing a correspondingconductive resistance sheet 60 when the main body-side vacuum adiabaticbody is closed with respect to the door-side vacuum adiabatic body. Inorder to reduce heat loss even when the main body and the door areopened, the shielding part 62 may be preferably provided as a porousmaterial or a separate adiabatic structure.

A conductive resistance sheet proposed in FIG. 4b may be preferablyapplied to the door-side vacuum adiabatic body. In FIG. 4b , portionsdifferent from those of FIG. 4a are described in detail, and the samedescription is applied to portions identical to those of FIG. 4a . Aside frame 70 is further provided at an outside of the conductiveresistance sheet 60. A part for sealing between the door and the mainbody, an exhaust port necessary for an exhaust process, a getter portfor vacuum maintenance, and the like may be placed on the side frame 70.This is because the mounting of parts is convenient in the mainbody-side vacuum adiabatic body, but the mounting positions of parts arelimited in the door-side vacuum adiabatic body.

In the door-side vacuum adiabatic body, it is difficult to place theconductive resistance sheet 60 at a front end portion of the vacuumspace part, i.e., a corner side portion of the vacuum space part. Thisis because, unlike the main body, a corner edge portion of the door isexposed to the exterior. More specifically, if the conductive resistancesheet 60 is placed at the front end portion of the vacuum space part,the corner edge portion of the door is exposed to the exterior, andhence there is a disadvantage in that a separate adiabatic part shouldbe configured so as to heat-insulate the conductive resistance sheet 60.

A conductive resistance sheet proposed in FIG. 4c may be preferablyinstalled in the pipeline passing through the vacuum space part. In FIG.4c , portions different from those of FIGS. 4a and 4b are described indetail, and the same description is applied to portions identical tothose of FIGS. 4a and 4b . A conductive resistance sheet having the sameshape as that of FIG. 4a , preferably, a wrinkled conductive resistancesheet 63 may be provided at a peripheral portion of the pipeline 64.Accordingly, a heat transfer path can be lengthened, and deformationcaused by a pressure difference can be prevented. In addition, aseparate shielding part may be provided to improve the adiabaticperformance of the conductive resistance sheet.

A heat transfer path between the first and second plate members 10 and20 will be described with reference back to FIG. 4a . Heat passingthrough the vacuum adiabatic body may be divided into surface conductionheat {circle around (1)} conducted along a surface of the vacuumadiabatic body, more specifically, the conductive resistance sheet 60,supporter conduction heat {circle around (2)} conducted along thesupporting unit 30 provided inside the vacuum adiabatic body, gasconduction heat (or convection {circle around (3)} conducted through aninternal gas in the vacuum space part, and radiation transfer heat{circle around (4)} transferred through the vacuum space part.

The transfer heat may be changed depending on various design dimensions.For example, the supporting unit may be changed such that the first andsecond plate members 10 and 20 can endure a vacuum pressure withoutbeing deformed, the vacuum pressure may be changed, the distance betweenthe plate members may be changed, and the length of the conductiveresistance sheet may be changed. The transfer heat may be changeddepending on a difference in temperature between the spaces (the firstand second spaces) respectively provided by the plate members. In theembodiment, a preferred configuration of the vacuum adiabatic body hasbeen found by considering that its total heat transfer amount is smallerthan that of a typical adiabatic structure formed by foamingpolyurethane. In a typical refrigerator including the adiabaticstructure formed by foaming the polyurethane, an effective heat transfercoefficient may be proposed as 19.6 mW/mK.

By performing a relative analysis on heat transfer amounts of the vacuumadiabatic body of the embodiment, a heat transfer amount by the gasconduction heat {circle around (3)} can become smallest. For example,the heat transfer amount by the gas conduction heat {circle around (3)}may be controlled to be equal to or smaller than 4% of the total heattransfer amount. A heat transfer amount by solid conduction heat definedas a sum of the surface conduction heat {circle around (1)} and thesupporter conduction heat {circle around (2)} is largest. For example,the heat transfer amount by the solid conduction heat may reach 75% ofthe total heat transfer amount. A heat transfer amount by the radiationtransfer heat {circle around (4)} is smaller than the heat transferamount by the solid conduction heat but larger than the heat transferamount of the gas conduction heat {circle around (3)}. For example, theheat transfer amount by the radiation transfer heat {circle around (4)}may occupy about 20% of the total heat transfer amount.

According to such a heat transfer distribution, effective heat transfercoefficients (eK: effective K) (W/mK) of the surface conduction heat{circle around (1)}, the supporter conduction heat {circle around (2)},the gas conduction heat {circle around (3)}, and the radiation transferheat {circle around (4)} may have an order of Math FIG. 1.

eK _(solidconductionheat) >eK _(radiationtransferheat) >eK_(gasconductionheat)  [Math Figure 1]

Here, the effective heat transfer coefficient (eK) is a value that canbe measured using a shape and temperature differences of a targetproduct. The effective heat transfer coefficient (eK) is a value thatcan be obtained by measuring a total heat transfer amount and atemperature of at least one portion at which heat is transferred. Forexample, a calorific value (W) is measured using a heating source thatcan be quantitatively measured in the refrigerator, a temperaturedistribution (K) of the door is measured using heats respectivelytransferred through a main body and an edge of the door of therefrigerator, and a path through which heat is transferred is calculatedas a conversion value (m), thereby evaluating an effective heat transfercoefficient.

The effective heat transfer coefficient (eK) of the entire vacuumadiabatic body is a value given by k=QL/AΔT. Here, Q denotes a calorificvalue (W) and may be obtained using a calorific value of a heater. Adenotes a sectional area (m2) of the vacuum adiabatic body, L denotes athickness (m) of the vacuum adiabatic body, and ΔT denotes a temperaturedifference.

For the surface conduction heat, a conductive calorific value may beobtained through a temperature difference (ΔT) between an entrance andan exit of the conductive resistance sheet 60 or 63, a sectional area(A) of the conductive resistance sheet, a length (L) of the conductiveresistance sheet, and a thermal conductivity (k) of the conductiveresistance sheet (the thermal conductivity of the conductive resistancesheet is a material property of a material and can be obtained inadvance). For the supporter conduction heat, a conductive calorificvalue may be obtained through a temperature difference (ΔT) between anentrance and an exit of the supporting unit 30, a sectional area (A) ofthe supporting unit, a length (L) of the supporting unit, and a thermalconductivity (k) of the supporting unit.

Here, the thermal conductivity of the supporting unit is a materialproperty of a material and can be obtained in advance. The sum of thegas conduction heat {circle around (3)}, and the radiation transfer heat{circle around (4)} may be obtained by subtracting the surfaceconduction heat and the supporter conduction heat from the heat transferamount of the entire vacuum adiabatic body. A ratio of the gasconduction heat {circle around (3)}, and the radiation transfer heat{circle around (4)} may be obtained by evaluating radiation transferheat when no gas conduction heat exists by remarkably lowering a vacuumdegree of the vacuum space part 50.

When a porous material is provided inside the vacuum space part 50,porous material conduction heat {circle around (5)} may be a sum of thesupporter conduction heat {circle around (2)} and the radiation transferheat {circle around (4)}. The porous material conduction heat {circlearound (5)} may be changed depending on various variables including akind, an amount, and the like of the porous material.

According to an embodiment, a temperature difference ΔT1 between ageometric center formed by adjacent bars 31 and a point at which each ofthe bars 31 is located may be preferably provided to be less than 0.5°C. Also, a temperature difference ΔT2 between the geometric centerformed by the adjacent bars 31 and an edge portion of the vacuumadiabatic body may be preferably provided to be less than 0.5° C. In thesecond plate member 20, a temperature difference between an averagetemperature of the second plate and a temperature at a point at which aheat transfer path passing through the conductive resistance sheet 60 or63 meets the second plate may be largest.

For example, when the second space is a region hotter than the firstspace, the temperature at the point at which the heat transfer pathpassing through the conductive resistance sheet meets the second platemember becomes lowest. Similarly, when the second space is a regioncolder than the first space, the temperature at the point at which theheat transfer path passing through the conductive resistance sheet meetsthe second plate member becomes highest.

This means that the amount of heat transferred through other pointsexcept the surface conduction heat passing through the conductiveresistance sheet should be controlled, and the entire heat transferamount satisfying the vacuum adiabatic body can be achieved only whenthe surface conduction heat occupies the largest heat transfer amount.To this end, a temperature variation of the conductive resistance sheetmay be controlled to be larger than that of the plate member.

Physical characteristics of the parts constituting the vacuum adiabaticbody will be described. In the vacuum adiabatic body, a force by vacuumpressure is applied to all of the parts. Therefore, a material having astrength (N/m2) of a certain level may be preferably used.

Under such circumferences, the plate members 10 and 20 and the sideframe 70 may be preferably made of a material having a sufficientstrength with which they are not damaged by even vacuum pressure. Forexample, when the number of bars 31 is decreased so as to limit thesupport conduction heat, deformation of the plate member occurs due tothe vacuum pressure, which may be a bad influence on the externalappearance of refrigerator. The radiation resistance sheet 32 may bepreferably made of a material that has a low emissivity and can beeasily subjected to thin film processing. Also, the radiation resistancesheet 32 is to ensure a strength high enough not to be deformed by anexternal impact. The supporting unit 30 is provided with a strength highenough to support the force by the vacuum pressure and endure anexternal impact, and is to have machinability. The conductive resistancesheet 60 may be preferably made of a material that has a thin plateshape and can endure the vacuum pressure.

In an embodiment, the plate member, the side frame, and the conductiveresistance sheet may be made of stainless materials having the samestrength. The radiation resistance sheet may be made of aluminum havinga weaker strength that the stainless materials. The supporting unit maybe made of resin having a weaker strength than the aluminum.

Unlike the strength from the point of view of materials, analysis fromthe point of view of stiffness is required. The stiffness (N/m) is aproperty that would not be easily deformed. Although the same materialis used, its stiffness may be changed depending on its shape. Theconductive resistance sheets 60 or 63 may be made of a material having apredetermined strength, but the stiffness of the material is preferablylow so as to increase heat resistance and minimize radiation heat as theconductive resistance sheet is uniformly spread without any roughnesswhen the vacuum pressure is applied. The radiation resistance sheet 32requires a stiffness of a certain level so as not to contact anotherpart due to deformation. Particularly, an edge portion of the radiationresistance sheet may generate conduction heat due to drooping caused bythe self-load of the radiation resistance sheet. Therefore, a stiffnessof a certain level is required. The supporting unit 30 requires astiffness high enough to endure a compressive stress from the platemember and an external impact.

In an embodiment, the plate member and the side frame may preferablyhave the highest stiffness so as to prevent deformation caused by thevacuum pressure. The supporting unit, particularly, the bar maypreferably have the second highest stiffness. The radiation resistancesheet may preferably have a stiffness that is lower than that of thesupporting unit but higher than that of the conductive resistance sheet.

The conductive resistance sheet may be preferably made of a materialthat is easily deformed by the vacuum pressure and has the loweststiffness. Even when the porous material 33 is filled in the vacuumspace part 50, the conductive resistance sheet may preferably have thelowest stiffness, and the plate member and the side frame may preferablyhave the highest stiffness.

FIG. 5 is a sectional view of a conductive resistance sheet and a firstplate member. Referring to FIG. 5, the conductive resistance sheet 60 isconnected to the first plate member 10, and may resist heat conductionflowing along a wall of a vacuum space part. The conductive resistancesheet 60 includes curved parts or portions 63 and 65 formed to bedepressed into the vacuum space part and a mounting part or portion 67mounted on the first plate member 10.

A thickness t1 of the conductive resistance sheet 60 is formed thinnerthan that of the first plate member 10. As the thickness t1 of theconductive resistance sheet 60 is decreased, heat transfer through thefirst plate member 10 is minimized, thereby improving an adiabaticeffect. Specifically, in order to satisfy a thermal conductivitycondition, the thickness t1 of the conductive resistance sheet 60 is tobe designed to be 300 μm or less. However, in order to sustainatmospheric pressure, the conductive resistance sheet 60 is to bedesigned to have a predetermined thickness or more.

The thickness t1 of the conductive resistance sheet 60 may be formed ata level of 0.05 mm. However, the thickness t1 of the conductiveresistance sheet 60 may be differently determined depending on materialsand shapes of the conductive resistance sheet 60.

The conductive resistance sheet 60 may be made of a stainlesssteel-based, titanium-based, or iron-based material. This is because thematerial has a low thermal conductivity and a sufficiently high strengthproperty. Additionally, the conductive resistance sheet 60 may be madeof precipitation hardening stainless steel (AM350). The precipitationhardening stainless steel (AM350) has a strength three to four timesgreater than that of the existing stainless steel, and thus its damagerisk is reduced.

The curved parts 63 and 65 include a first curved part or portion 63 anda second curved part or portion 65. The first curved part 63 may beformed in a shape depressed toward the vacuum space part. The secondcurved part 65 extends from each of both ends of the first curved part63.

The second curved part 65 is disposed to surround an edge portion of thefirst plate member 10. Since the conductive resistance sheet 60 is madeof a thin material, the conductive resistance sheet 60 is weak tostrength. Thus, the edge portion of the first plate member 10 is formedto be rounded, so that a damage of the conductive resistance sheet 60can be prevented. Meanwhile, the edge portion of the first plate member10 may be chamfered to correspond to the direction in which the secondcurved part 65 is curved.

A coupling part (or seal) 61 for fixing the conductive resistance sheet60 to the first plate member 10 is formed on the mounting part 67. Thecoupling part 61 may be formed through welding. Therefore, the couplingpart 61 may be named as a welding part.

Meanwhile, the conductive resistance sheet 60 may be made of a similarmaterial to the first plate member 10. This is for the purpose thatwelding between the conductive resistance sheet 60 and the first platemember 110 is smoothly performed.

When the mounting part 67 is welded to the first plate member 10, a gapmay be generated between the mounting part 67 and the first plate member10 as deformation of the conductive resistance sheet 60 is caused byheat. In this case, the vacuum degree of the vacuum space part is notmaintained, and therefore, the adiabatic effect may be reduced. Thus, inwelding of when the mounting part 67 is welded to the first plate member10, the welding is to be performed after the periphery of a portion tobe welded is pressed using a jig. Accordingly, the mounting part 67 canbe adhered closely to the first plate member 10.

The welding part 61 may be spaced apart from the edge portion of thefirst plate member 10 at a predetermined length. Specifically, a lengthd1 from the welding part 61 to a boundary part (or boundary) 66 betweenthe second curved part 65 and the mounting part 67 is to be ensured aslong as a space to be pressed using the jig. The length d1 may be set toa minimum of 5 mm or so. In this case, a length d2 from the welding part61 to a boundary part (or boundary) 64 between the first curved part 63and the second curved part 65 may be designed to be 7 mm or more.

The first curved part 63 is formed in a downwardly convex shape, and thesecond curved part 65 is formed in an upwardly convex shape. That is, acurvature R1 of the first curved part 63 and a curvature R2 of thesecond curved part 65 have different signs from each other. The boundarypart 64 between the first curved part 63 and the second curved part 65may be formed such that the curvature of the boundary part 64 becomes 0.The curvature R2 of the second curved part 65 may satisfy the followingrelationship.

$\begin{matrix}{{R\; 2} > \frac{t\; 2}{10}} & \lbrack {{Math}\mspace{14mu} {Figure}\mspace{14mu} 2} \rbrack\end{matrix}$

Here, t2 denotes a vertical distance from the mounting part 67 to theboundary part 64 between the first curved part 63 and the second curvedpart 65. The second curved part 65 forms a curved surface and themounting part 67 forms a plane. Therefore, based on the boundary part 66between the second curved part 65 and the mounting part 67, its leftside forms a plane and its right side forms a curved surface.

FIG. 6 is a graph illustrating a design reference of the conductiveresistance sheet. Referring to FIG. 6, the following formula between xand y is applied to the graph.

y=30.198x ⁻⁰⁸⁴⁴  [Math Figure 3]

Here, x denotes (depth of conductive resistance sheet)/(width ofconductive resistance sheet)∧2, and y denotes (minimum thickness ofconductive resistance sheet)*(permissible strength of conductiveresistance sheet). That is, if a depth, a width, and a permissiblestrength of the conductive resistance sheet 60 are known, a minimumthickness t1 of the conductive resistance sheet 60 can be evaluated.Here, the permissible strength of the conductive resistance sheet 60corresponds to 240 MPa that is a rupture strength. However, thepermissible strength may be changed depending on a material of theconductive resistance sheet 60.

The depth H of the conductive resistance sheet 60 refers to a verticaldistance from the mounting part 67 to the lowest point of the firstcurved part 63. The width L of the conductive resistance sheet 60 refersto a width of the conductive resistance sheet 60 in the horizontaldirection. The permissible strength of the conductive resistance sheet60 is a value determined depending on a material of the conductiveresistance sheet 60.

Through the graph, if the width L of the conductive resistance sheet 60is constant, the minimum thickness of the conductive resistance sheet 60is exponentially increased as the depth H of the conductive resistancesheet 60 is decreased. Thus, the section of the conductive resistancesheet 60 forms a semicircular or arch shape, so that the minimumthickness of the conductive resistance sheet 60 can be decreased.Accordingly, it is possible to improve adiabatic performance.

The thickness of the conductive resistance sheet 60 is to be formed tobe 300 μm or less. This is because, as the thickness of the conductiveresistance sheet 60 is decreased, an effect of blocking cold airtransferred from the first plate member 10 is increased. That is, as thethickness of the conductive resistance sheet 60 is decreased, thethermal conductivity of the conductive resistance sheet 60 may bedecreased.

Meanwhile, in order to satisfy a minimum strength condition and anoptimal volume condition, the range of thickness of the vacuum adiabaticbody may be designed to be equal to or greater than 3 mm and equal to orsmaller than 30 mm. When the conductive resistance sheet 60 is disposedas shown in FIG. 4a , the diameter of a semicircle formed by the sectionof the conductive resistance sheet 60 may approximate to the thicknessof the vacuum adiabatic body, and therefore, the range of diameter of asemicircle formed by the section of the conductive resistance sheet 60is also designed to be equal to or greater than 3 mm and equal to orsmaller than 30 mm. Accordingly, like the range of radius of thesemicircle formed by the section of the conductive resistance sheet 60,the range of depth of the conductive resistance sheet 60 is designed tobe equal to or greater than 1.5 mm and equal to or smaller than 15 mm.

If the range of depth of the conductive resistance sheet 60 is equal toor greater than 1.5 mm and equal to or smaller than 15 mm, and the rangeof width of the conductive resistance sheet 60 is equal to or greaterthan 3 mm and equal to or smaller than 30 mm, the range of x on thegraph corresponds to a range of 0.016 to 0.167. If the permissiblestrength of the conductive resistance sheet 60 is calculated as 240 MPa,the range of minimum thickness of the conductive resistance sheet 60 maybe set to be equal to or greater than 0.57 μm and equal to or smallerthan 3.98 μm. That is, when the thickness of the vacuum adiabatic bodyis designed to satisfy the minimum strength condition and the optimalvolume condition, the range of minimum thickness of the conductiveresistance sheet 60 may be designed to be equal to or greater than 0.57μm and equal to or smaller than 3.98 μm.

FIG. 7 is a view showing a state in which atmospheric pressure isapplied to the conductive resistance sheet. FIG. 8 is a viewillustrating a relationship between the atmospheric pressure and atension applied to the conductive resistance sheet.

Referring to FIGS. 7 and 8, a total load applied to the conductiveresistance sheet 60 corresponds to a multiplication of the atmosphericpressure and the width L of the conductive resistance sheet 60. Adistributed load caused by the atmospheric pressure is verticallyapplied to a surface of the conductive resistance sheet 60. If thedistributed load is integrated, the distributed load may be representedas one concentrated load. Here, the magnitude of the concentrated loadis a multiplication of the width L of the conductive resistance sheet 60and the atmospheric pressure, and the direction of the concentrated loadis a direction in which the concentrated load is applied to the middleof the conductive resistance sheet 60.

When the atmospheric pressure applied to the conductive resistance sheet60 and the tension applied to both ends of the conductive resistancesheet 60 maintain balance, the following relationship is satisfied.

2F _(y) =P  [Math Figure 4]

Here, Fy and P satisfy the following formula.

F _(y) =σt Sin θ,P=AL  [Math Figure 5]

Here, α denotes a stress applied to the conductive resistance sheet 60,t denotes a thickness of the conductive resistance sheet 60, A denotesatmospheric pressure, and L denotes a width of the conductive resistancesheet 60.

Therefore, the stress α applied to the conductive resistance sheet 60satisfies the following formula.

$\begin{matrix}{\sigma = \frac{AL}{t\; \sin \; \theta}} & \lbrack {{Math}\mspace{14mu} {Figure}\mspace{14mu} 6} \rbrack\end{matrix}$

The strength of the conductive resistance sheet 60 is to be equal to orgreater than the stress, and is to be set as large as possible so as todecrease the stress applied to the conductive resistance sheet 60. Thatis, it is advantageous in that the conductive resistance sheet 60 has ashape close to that of a semicircle. In addition, the stress applied tothe conductive resistance sheet 60 can be decreased even when thethickness t of the conductive resistance sheet 60 is increased.

Hereinafter, a vacuum pressure preferably determined depending on aninternal state of the vacuum adiabatic body will be described. Asalready described above, a vacuum pressure is to be maintained insidethe vacuum adiabatic body so as to reduce heat transfer. At this time,it will be easily expected that the vacuum pressure is preferablymaintained as low as possible so as to reduce the heat transfer.

The vacuum space part 50 may resist the heat transfer by applying onlythe supporting unit 30. Alternatively, the porous material 33 may befilled together with the supporting unit in the vacuum space part 50 toresist the heat transfer. Alternatively, the vacuum space part mayresist the heat transfer not by applying the supporting unit but byapplying the porous material 33.

The case where only the supporting unit is applied will be described.FIG. 9 illustrates graphs showing changes in adiabatic performance andchanges in gas conductivity with respect to vacuum pressures by applyinga simulation. Referring to FIG. 9, it can be seen that, as the vacuumpressure is decreased, i.e., as the vacuum degree is increased, a heatload in the case of only the main body (Graph 1) or in the case wherethe main body and the door are joined together (Graph 2) is decreased ascompared with that in the case of the typical product formed by foamingpolyurethane, thereby improving the adiabatic performance. However, itcan be seen that the degree of improvement of the adiabatic performanceis gradually lowered. Also, it can be seen that, as the vacuum pressureis decreased, the gas conductivity (Graph 3) is decreased.

However, it can be seen that, although the vacuum pressure is decreased,the ratio at which the adiabatic performance and the gas conductivityare improved is gradually lowered. Therefore, it is preferable that thevacuum pressure is decreased as low as possible. However, it takes longtime to obtain excessive vacuum pressure, and much cost is consumed dueto excessive use of a getter. In the embodiment, an optimal vacuumpressure is proposed from the above-described point of view.

FIG. 10 illustrates graphs obtained by observing, over time andpressure, a process of exhausting the interior of the vacuum adiabaticbody when the supporting unit is used. Referring to FIG. 10, in order tocreate the vacuum space part 50 to be in the vacuum state, a gas in thevacuum space part 50 is exhausted by a vacuum pump while evaporating alatent gas remaining in the parts of the vacuum space part 50 throughbaking. However, if the vacuum pressure reaches a certain level or more,there exists a point at which the level of the vacuum pressure is notincreased any more (Δt1).

After that, the getter is activated by disconnecting the vacuum spacepart 50 from the vacuum pump and applying heat to the vacuum space part50 (Δt2). If the getter is activated, the pressure in the vacuum spacepart 50 is decreased for a certain period of time, but then normalizedto maintain a vacuum pressure of a certain level. The vacuum pressurethat maintains the certain level after the activation of the getter isapproximately 1.8×10∧(−6) Torr. In the embodiment, a point at which thevacuum pressure is not substantially decreased any more even though thegas is exhausted by operating the vacuum pump is set to the lowest limitof the vacuum pressure used in the vacuum adiabatic body, therebysetting the minimum internal pressure of the vacuum space part 50 to1.8×10∧(−6) Torr.

FIG. 11 illustrates graphs obtained by comparing vacuum pressures andgas conductivities. Referring to FIG. 11, gas conductivities withrespect to vacuum pressures depending on sizes of a gap in the vacuumspace part 50 are represented as graphs of effective heat transfercoefficients (eK). Effective heat transfer coefficients (eK) weremeasured when the gap in the vacuum space part 50 has three sizes of2.76 mm, 6.5 mm, and 12.5 mm.

The gap in the vacuum space part 50 is defined as follows. When theradiation resistance sheet 32 exists inside vacuum space part 50, thegap is a distance between the radiation resistance sheet 32 and theplate member adjacent thereto. When the radiation resistance sheet 32does not exist inside vacuum space part 50, the gap is a distancebetween the first and second plate members.

It can be seen that, since the size of the gap is small at a pointcorresponding to a typical effective heat transfer coefficient of 0.0196W/mK, which is provided to an adiabatic material formed by foamingpolyurethane, the vacuum pressure is 2.65×10∧(−1) Torr even when thesize of the gap is 2.76 mm. Meanwhile, it can be seen that the point atwhich reduction in adiabatic effect caused by gas conduction heat issaturated even though the vacuum pressure is decreased is a point atwhich the vacuum pressure is approximately 4.5×10∧(−3) Torr. The vacuumpressure of 4.5×10∧(−3) Torr can be defined as the point at which thereduction in adiabatic effect caused by gas conduction heat issaturated. Also, when the effective heat transfer coefficient is 0.1W/mK, the vacuum pressure is 1.2×10∧(−2) Torr.

When the vacuum space part 50 is not provided with the supporting unitbut provided with the porous material, the size of the gap ranges from afew micrometers to a few hundredths of micrometers. In this case, theamount of radiation heat transfer is small due to the porous materialeven when the vacuum pressure is relatively high, i.e., when the vacuumdegree is low. Therefore, an appropriate vacuum pump is used to adjustthe vacuum pressure. The vacuum pressure appropriate to thecorresponding vacuum pump is approximately 2.0×10∧(−4) Torr.

Also, the vacuum pressure at the point at which the reduction inadiabatic effect caused by gas conduction heat is saturated isapproximately 4.7×10∧(−2) Torr. Also, the pressure where the reductionin adiabatic effect caused by gas conduction heat reaches the typicaleffective heat transfer coefficient of 0.0196 W/mK is 730 Torr. When thesupporting unit and the porous material are provided together in thevacuum space part, a vacuum pressure may be created and used, which ismiddle between the vacuum pressure when only the supporting unit is usedand the vacuum pressure when only the porous material is used.

The vacuum adiabatic body proposed in the present disclosure may bepreferably applied to refrigerators. However, the application of thevacuum adiabatic body is not limited to the refrigerators, and may beapplied in various apparatuses such as cryogenic refrigeratingapparatuses, heating apparatuses, and ventilation apparatuses.

According to the present disclosure, the vacuum adiabatic body can beindustrially applied to various adiabatic apparatuses. The adiabaticeffect can be enhanced, so that it is possible to improve energy useefficiency and to increase the effective volume of an apparatus.

Embodiments provide a vacuum adiabatic body and a refrigerator, whichcan obtain a sufficient adiabatic effect in a vacuum state and beapplied commercially.

In one embodiment, a vacuum adiabatic body includes: a first platemember defining at least one portion of a wall for a first space; asecond plate member defining at least one portion of a wall for a secondspace having a different temperature from the first space; a sealingpart sealing the first plate member and the second plate member toprovide a third space that has a temperature between the temperature ofthe first space and the temperature of the second space and is in avacuum state; a supporting unit maintaining the third space; a heatresistance unit for decreasing a heat transfer amount between the firstplate member and the second plate member; and an exhaust port throughwhich a gas in the third space is exhausted, wherein the heat resistanceunit includes a conductive resistance sheet connected to at least one ofthe first and second plate members, the conductive resistance sheetresisting heat conduction flowing along a wall for the third space, theconductive resistance sheet includes a mounting part mounted on theplate member and a curved part having at least one portion depressedinto the third space, a coupling part for fixing the conductiveresistance sheet to the plate member is formed on the mounting part, andthe curved part includes a first curved part depressed toward the thirdspace and a second curved part extending from the first curved part, thesecond curved part surrounding an edge portion of the plate member.

In another embodiment, a vacuum adiabatic body includes: a first platemember defining at least one portion of a wall for a first space; asecond plate member defining at least one portion of a wall for a secondspace having a different temperature from the first space; a sealingpart sealing the first plate member and the second plate member toprovide a third space that has a temperature between the temperature ofthe first space and the temperature of the second space and is in avacuum state; a supporting unit maintaining the third space; a heatresistance unit for decreasing a heat transfer amount between the firstplate member and the second plate member; and an exhaust port throughwhich a gas in the third space is exhausted, wherein the heat resistanceunit includes a conductive resistance sheet connected to at least one ofthe first and second plate members, the conductive resistance sheetresisting heat conduction flowing along a wall for the third space, andthe conductive resistance sheet includes a curved part formed to bedepressed into the third space by a pressure difference and a mountingpart provided at each of both ends of the curved part, the mounting partbeing mounted on the plate member.

In still another embodiment, a refrigerator includes: a main bodyprovided with an internal space in which storage goods are stored; and adoor provided to open/close the main body from an external space,wherein, in order to supply a refrigerant into the internal space, therefrigerator includes: a compressor for compressing the refrigerant; acondenser for condensing the compressed refrigerant; an expander forexpanding the condensed refrigerant; and an evaporator for evaporatingthe expanded refrigerant to take heat, wherein at least one of the mainbody and the door includes a vacuum adiabatic body, wherein the vacuumadiabatic body includes: a first plate member defining at least oneportion of a wall for the internal space; a second plate member definingat least one portion of a wall for the external space; a sealing partsealing the first plate member and the second plate member to provide avacuum space part that has a temperature between a temperature of theinternal space and a temperature of the external space and is in avacuum state; a supporting unit maintaining the vacuum space part; aheat resistance unit for decreasing a heat transfer amount between thefirst plate member and the second plate member; and an exhaust portthrough which a gas in the vacuum space part is exhausted, wherein theheat resistance unit includes a conductive resistance sheet connected toat least one of the first and second plate members, the conductiveresistance sheet resisting heat conduction flowing along a wall for thevacuum space part, and the conductive resistance sheet includes a curvedpart having at least one portion depressed into the vacuum space partand a mounting part mounted on the plate member.

According to the present disclosure, it is possible to provide a vacuumadiabatic body having a vacuum adiabatic effect and a refrigeratorincluding the same.

Any reference in this specification to “one embodiment,” “anembodiment,” “example embodiment,” etc., means that a particularfeature, structure, or characteristic described in connection with theembodiment is included in at least one embodiment of the invention. Theappearances of such phrases in various places in the specification arenot necessarily all referring to the same embodiment. Further, when aparticular feature, structure, or characteristic is described inconnection with any embodiment, it is submitted that it is within thepurview of one skilled in the art to effect such feature, structure, orcharacteristic in connection with other ones of the embodiments.

Although embodiments have been described with reference to a number ofillustrative embodiments thereof, it should be understood that numerousother modifications and embodiments can be devised by those skilled inthe art that will fall within the spirit and scope of the principles ofthis disclosure. More particularly, various variations and modificationsare possible in the component parts and/or arrangements of the subjectcombination arrangement within the scope of the disclosure, the drawingsand the appended claims. In addition to variations and modifications inthe component parts and/or arrangements, alternative uses will also beapparent to those skilled in the art.

What is claimed is:
 1. A vacuum adiabatic body comprising: a firstplate; a second plate; a seal that seals the first plate and the secondplate to provide a space to be in a vacuum state; a support thatsupports the first and second plates, and is provided in the space; aconductive resistance sheet connected to at least one of the first plateand the second plate, the conductive resistance sheet configured toresist heat transfer; wherein the conductive resistance sheet includes:a mounting portion mounted on the first plate; and a curved portionhaving at least one portion depressed into the space, wherein the curvedportion includes: a first curved portion recessed into the space, and asecond curved portion that extends from the first curved portion; andwherein the seal includes a coupling part disposed on the mountingportion to attach the conductive resistance sheet to the first plate. 2.The vacuum adiabatic body according to claim 1, wherein the secondcurved portion surrounds the first plate.
 3. The vacuum adiabatic bodyaccording to claim 2, wherein the second curved portion surrounds anedge of the first plate.
 4. The vacuum adiabatic body according to claim1, wherein a boundary between the first curved portion and the secondcurved portion has a curvature of
 0. 5. The vacuum adiabatic bodyaccording to claim 1, wherein the seal includes a welding part.
 6. Thevacuum adiabatic body according to claim 1, wherein the conductiveresistance sheet is made of a stainless steel-based material, atitanium-based material, or an iron-based material.
 7. The vacuumadiabatic body according to claim 1, wherein a thickness of theconductive resistance sheet is less than a thickness of the first plate.8. The vacuum adiabatic body according to claim 1, wherein a vacuumdegree of the space is equal to or greater than 1.8×10∧(−6) Torr, and isequal to or smaller than 2.65×10∧(−1) Torr.
 9. The vacuum adiabatic bodyaccording to claim 1, wherein a stiffness of the conductive resistancesheet is less than a stiffness of the first plate.
 10. The vacuumadiabatic body according to claim 1, wherein the second curved portionextends from each of both ends of the first curved portion.
 11. Thevacuum adiabatic body according to claim 1, wherein the mounting portionis spaced apart from the second curved portion.
 12. The vacuum adiabaticbody according to claim 1, wherein the second curved portion is curvedin a different direction than the first curved portion.
 13. The vacuumadiabatic body according to claim 12, wherein a curvature of the firstcurved portion is larger than a curvature of the second curved portion.14. The vacuum adiabatic body according to claim 1, wherein the secondcurved part forms a curved surface, and the mounting portion forms aplane.
 15. The vacuum adiabatic body according to claim 1, wherein aporous material is provided in the space.
 16. A refrigerator comprising:a main body including an internal space; and a door provided to open andclose the main body, wherein, in order to supply a refrigerant into themain body, the refrigerator includes: a compressor that compresses therefrigerant; a condenser that condenses the compressed refrigerant; anexpander that expands the condensed refrigerant; and an evaporator thatevaporates the expanded refrigerant to transfer heat, wherein at leastone of the main body and the door includes the vacuum adiabatic body ofclaim
 1. 17. A vacuum adiabatic body comprising: a first plate; a secondplate; a seal that seals the first plate and the second plate to providea space to be in a vacuum state; a support that supports the first andsecond plates, and is provided in the space; and a conductive resistancesheet connected to at least one of the first plate and the second plate,the conductive resistance sheet configured to resist heat transfer;wherein the conductive resistance sheet includes: a mounting portionmounted on the first plate and attached to the first plate by a part ofthe seal; and a curved portion that includes: a first curved portion toextend into the space, and a second curved portion to extend from thefirst curved portion to the mounting portion.
 18. The vacuum adiabaticbody according to claim 17, wherein the second curved portion surroundsan edge of the first plate.
 19. A vacuum adiabatic body comprising: afirst plate; a second plate; a seal that seals the vacuum adiabatic bodyto provide a space in a vacuum state; a support provided in the space tosupport the first and second plates; and a conductive resistance sheetconfigured to reduce heat transfer between the second plate and thefirst plate; wherein the conductive resistance sheet includes: amounting portion on the first plate; and a curved portion that extendsfrom the mounting portion into the space, wherein at least a part of theseal is disposed on the mounting portion to attach the conductiveresistance sheet to the first plate, wherein the curved portionincludes: a first curved part to extend toward the second plate, and asecond curved part to extend from the first curved part to the mountingportion.
 20. The vacuum adiabatic body according to claim 19, whereinthe second curved part surrounds an edge of the first plate.